The present invention relates to apparatus for processing rolls of convoluted paper or other flexible sheet material. More particularly, the invention relates to improvements in apparatus wherein the processing of relatively large paper rolls or the like (hereinafter called rolls for short with the understanding that this term is intended to embrace rolls of any desired diameter and/or axial length as well as rolls which consist of paper, metallic or plastic foil, cardboard and/or any other sheet material which can be convoluted onto a core to form a cylindrical body) involves, among others, the draping of each roll into a blank of suitable wrapping material. Still more particularly, the invention relates to improvements in apparatus for treating rolls with centrally located recesses in one or both end faces thereof (such recesses can form part of an uninterrupted axial hole in the roll, or an uninterrupted hole or bore in an elongated tubular core around which the windings of the roll are convoluted and which may but need not be removable or withdrawable from the innermost convolution of the coiled flexible sheet material, or which can constitute sockets in cylindrical or similar plugs recessed into the respective end faces of the roll).
The assignee of the present application manufactures and offers for sale a processing machine (known as Kleinewefers Rollenpackmaschine Typ 6.6) wherein a discrete disc-shaped inner cover (hereinafter called inner disc) is placed adjacent to each end face of each of a series of successive rolls while the axes of the rolls are maintained in horizontal or nearly horizontal positions. Successive rolls are thereupon rotated about their axes during application of blanks of wrapping material (e.g., lightweight cardboard) to their peripheral surfaces in such a way that the marginal portions of each blank extend beyond the respective end faces of the corresponding roll. In the next step, the thus coarsely draped roll is introduced into a folding unit which folds the projecting marginal portions of the respective blank over the adjacent end faces of the roll before the roll is introduced into the space between two pressure-applying plates serving to apply disc-shaped outer covers (hereinafter called outer discs) over the respective folded-over marginal portions to thereby complete the confinement of each roll in a hollow cylindrical envelope having a cylindrical shell surrounding the outermost convolution of the respective roll and two composite end walls each including an inner disc and an outer disc as well as the suitably deformed or folded corresponding marginal portion of the blank therebetween. The just discussed apparatus of the assignee further comprises suitable units which deliver the rolls to various stations, which remove finished products (wrapped rolls) from the last station, and which transport the rolls (with or without portions of their envelopes) between successive stations. Still further, the just discussed apparatus comprises various sensors, means for applying adhesive to selected portions of the discs and/or blanks, and/or other components which allow for semiautomatic or fully automatic processing of rolls on the way to storage or to another destination, e.g., to conveyances which transport finished products to customers.
The means for delivering successive rolls of a short or long series of rolls to the first station of the aforediscussed apparatus of the assignee of the present invention comprises a conveyor system which moves successive rolls axially so that a portion of the peripheral surface of each roll rests on a mobile support in the form of a belt conveyor. A pusher or another suitable ejecting device is provided to transfer the rolls from the belt conveyor onto an inclined surface along which successive rolls roll by gravity and where the progress of the rolls is controlled by suitable regulating elements in the form of mobile stops or the like so that each roll advances into the range of a centering device. The centering device is disposed at the lower end of the inclined surface and includes two centering plates arranged to engage the end faces of an oncoming roll for the purpose of ensuring that such roll is halved by the imaginary central symmetry plane of the draping unit which is located immediately behind the centering device. The draping unit employs two driven rollers on which the freshly supplied and centered roll rests in horizontal position and which cause such roll to rotate about its own axis. The draping unit further comprises several sources of wrapping material (each such source includes a supply of convoluted draping material having a predetermined width and means for selecting that source which is best suited for adequate draping of the roll at the draping station (i.e., for selecting a source which supplies wrapping material in the form of a web having a width exceeding the axial length of the roll at the draping station by a preselected value to thus ensure that each marginal portion will project beyond the respective end face of the roll to an extent which is needed for the making of a sufficiently strong hollow cylindrical envelope without excessive waste in wrapping material). The selected web of wrapping material is caused to run along a paster containing a supply of suitable adhesive paste, and the web is thereupon advanced between the aforementioned driven rollers and the roll at the draping station. Pivotable or otherwise movable belts, bands or analogous guide elements are provided to properly guide the web of selected wrapping material at the draping station. The roll is thereupon transferred to the folding station which follows the draping station and where blades, wheels or otherwise configurated folding elements are employed to fold the marginal portions of the freshly convoluted blank over the respective end faces of the roll. During such treatment at the folding station, the roll again rests (in horizontal position) on two driven rollers which cause the roll to rotate about its own axis. When the folding operation is completed, the roll is caused to advance to the aforementioned pressure-applying station, namely, to the station where the folded-over marginal portions of a blank are concealed by outer discs. The thus finished roll thereupon advances onto a weighing device and to a belt conveyor which travels in a direction at right angles to the path of movement of the oncoming roll. A shock absorber is provided to arrest a finished product in the region of the belt conveyor which then advances the product by moving it axially while a portion of the cylindrical envelope rests on the upper reach of the conveyor.
The operation of the just discussed apparatus can be automated to a desired extent. This necessitates the provision of sensor means which ascertain the diameter and the axial length of each oncoming roll and generate appropriate signals which are used to select the width of wrapping material, the extent of axial and/or other displacement of the rolls, the extent of angular movement of rolls about their respective axes at the draping and/or other stations, and so forth. The operation of the aforediscussed known apparatus is highly satisfactory and, therefore, the apparatus has found widespread acceptance in the paper making, textile and many other industries. It has been found that such apparatus is especially suitable for rapid, economical and predictable processing of large and hence very heavy and bulky paper rolls. However, certain types of paper or other material of which the rolls consist necessitate an extremely careful and gentle treatment. For example, pressure-sensitive papers, such as carbon papers of the type known as or resembling so-called NCR papers, must be treated with utmost care in order to prevent undesirable defacing or marking of convolutions during treatment in the making plant. The same applies for many types of rolls consisting of very soft paper or of paper which is coiled or wound in the form of loose convolutions that should remain intact during wrapping, shipment and/or storage. The just discussed highly sensitive papers must be held out of contact with plungers or analogous ejectors, roller-shaped or otherwise configurated stops, shock absorbers and/or driver rollers which engage the periphery of a relatively large roll. Moreover, the folding, draping and/or certain other instrumentalities of apparatus for the treatment of such highly sensitive web or strip stock must be designed with a view to avoid the application of pronounced pressure to any part of a roll, i.e., to the convolutions which are confined when the roll is fully wound as well as to the outermost convolution of each roll.